title: Dissolved organic nitrogen regulation in freshwaters.
mesh_terms: D002244:Carbon / Q000737:chemistry; D004784:Environmental Monitoring / Q000379:methods; D005308:Fertilizers; D005618:Fresh Water / Q000737:chemistry*; D006801:Humans; D009566:Nitrates / Q000737:chemistry; D009584:Nitrogen / Q000737:chemistry*; D012621:Seasons; D014852:Wales; D014874:Water Pollutants, Chemical; D014876:Water Pollution / Q000517:prevention & control*
chemical_list: D005308:Fertilizers; D009566:Nitrates; D014874:Water Pollutants, Chemical; D002244:Carbon; D009584:Nitrogen